The 400 Series was a Japanese Shinkansen train operated by JR East between 1992 and 2010. They were originally six-car sets, but a seventh car was added in 1995 to each set due to their popularity. The fleet of twelve 400 series trains was scheduled to be withdrawn between December 2008 and summer 2009, replaced by new E3-2000 series trains. However, one set remained in service until 18 April 2010, with the date chosen to mark 18 years of service.Source: http://en.wikipedia.org/wiki/400_Series_Shinkansen